Structural floor



Nov. 5, 1929. R, v, YEAGER STRUCTURAL moon Filed Feb. 7, 1928 if js J419 Patented Nov. y5, 1929 UNITED STATES ROY v. YEAGER, or uns MOINES,IOWA STRUCTURAL Broca Application filed. February 7, 1928. Serial No.252,524.

My invention relates to that class of structural floors in whichstructural metal joists are employed, and the concrete floor issupported upon said joists, with all or part of 5 the joists ext-endedbelow the floor and fircproofed.

The object of my invention is to provide a structural floor of thischaracter to which fireproofing material, such gypsum, may be readilyand easilyl moulded about the lower portions of the joists, before thejoists are placed in position, and this -tireproofing material willfurnish a temporary support for the plaster boards between the joists.

In this connection, a further object is to provide a structural joistwhich may be adequately fireproofed with a minimum thickness offireproofingfmaterial. These plaster boards resting upon thefireprooiing material will form an adequate temporary Support for theconcrete licor in plastic condition, and when the floor has setandhardened, it will become bonded with the plaster board.

A further object of my invention is to provide a structural joist inwhich the top chord is made of two relatively small members spacedapart, and the lower ychord made of a single member, and whereby whenthe upper chord has become embedded in the set and hardened concrete, itwill be prevented from buckling due to compression strains by't1 il()action of the concrete in which the spaced apart upper chords areembedded. In this connection it should be explained that the or dinarystructural joints now in use are made with the cross sectional area ofthe upper chord much greater'than the cross sectional area of the lowerchord, whereas with my improved floor construction these structuraljoists are preferably made with the cross sec tional area of the upperchords the same as, or less than, the cross sectional area of the lowerchord, thus effecting a substantial saving in structural metal for thejoists.

My invention consists in the construction, arrangement and combinationof the various parts of the device, whereby the objects contemplated areattained, as hereinafter more fully set forth, pointed out in my claim,and

illustrated in the accompanying in which: f

Figure 1 shows a side elevation of a portion of a floor structure withfirejgn'ooiing material applied to the lower portion of the jcists, partof which is broken yaway to show the lower rchord member and withplaster board supported upon the fireproofing material, and shown insection, and with a concrete floor moulded upon the plaster board andabout the upper chord member, and shown in section.

Figure 2 shows a transverse sectional view on the line 2 2 of Figure 1;and

Figure 3 shows a transverse sectional view on the line 3 3 of Figure 1.k

Referring to the accompanying drawings, it will be seen that my improvedjoist comprises a lower chord made of one piece of metal, preferablyround in cross section. This chord comprises a horizontally arranged endmember 10 designed to rest on the structural beams or walls, a part 11eX- tending downwardly therefrom at an angle of about 415, and ahorizontally arranged central portion 12.y Resting on top of the endmembers 10 are reinforcing blocks 13, and resting against the sides ofthese reinforcing blocks are theupper chord members le and l5. Bracingmembers 16 are provided to connect the upper and lower chord members atintervals, and they are preferably welded to the top of the lower chordmember and extended between and welded to the upper chord members.

The cross sectional area of the upper chord members 14 is the same as,or less than, the

, cross sectional area of the lower chord member.

When a floor is being constructed, a suitable mould is provided and thelower chord member of each joist is placed centrally in the mould. Thenthere is applied in the mould gypsum fireproobfing material, or thelike, in plastic condition, which very soon sets and hardens, and whenthe joist is removed from the mould, the fireproofing material is bondedand anchored to it and forms an adequate fireproofing for the lowerchord member. The upper end of the ireprooing drawings,

material forms a horizontal shoulder which is spaced apart aconsiderable distance from the top chord member, which ireprootingmaterial is indicated by the numeral 1'?.

After the joists have been laid in position, layers of plaster board 18are placed in position between the joists and resting upon the top oftheiireproofing material 17. Then the concrete floor 19 in plasticcondition is placed on the plaster board and surrounds and, extendsabove the top of the upper chord members, and after the floor has setandl hardened.

the plaster board becomes bonded with the concrete floor.

In practical use, it is obvious with my improved' oor structure thereisv eiiected an economy in the amount of structural metal necessary forthe joists, because the lower chord has applied to it in use onlytension strains, and the upper chord member-has appliedto it onlycompression strains, and hence the upper chord members are embedded inrigid concrete that cannot buckle, and hence can be made with much lessmetal than could properly be used heretofore in iioor structures inwhich theA concrete floor was placed above the upper chords.

t willbe noted also that with my improved structural floor there is aneconomy in the amountfot1 fireproofingnecessary for the lower chord,because since the lower' chord is made ofy one piece of metal only, itis or" less diameter tromsideto side than if it were made of twoAmembers side by side, and hence the amount of lireproofing materialnecessary to adequately iireproof it isvgreatly reduced.

1 claim as my invention:

In a structural floor, the combination of a number of structural oists,each comprising a top chord made of two parallel chord membersspacedfapart laterally, a single lower chord member connected at itsends to the upper chord member with its central portion spaced below theupper chord member, braces secured to the lower chord member andprojected between and secured to the upper chord members, the transversedimensions of the two upper chord members being,` much greater than thetransverse diameter of the single lower chord member, a body ot'tireproof materialfor each beam moulded about and bonded to andcompletely surrounding the lower portion of each beam, and having at itsupper portion supporting shoulders ez:- tended laterally, plaster boardssupported upon said shoulders and extended from one beam to the other,and a concrete ioor supported upon the plaster boards and completelysurrounding and bonding` the upper portions of the beams.

Des Moines, IoWa,.J`anuary 20, 1928.

ROY V. YEAGER.

